334
AWUS01 KWNH 012235
FFGMPD
MSZ000-LAZ000-TXZ000-020410-

Mesoscale Precipitation Discussion 0369
NWS Weather Prediction Center College Park MD
634 PM EDT Sat Jun 01 2024

Areas affected...east Texas, much of Louisiana

Concerning...Heavy rainfall...Flash flooding possible

Valid 012210Z - 020410Z

Summary...Flash flood potential continues as a broad axis of
slow-moving storms (extending from near Longview to near
Alexandria, Baton Rouge, and Slidell) continue to produce locally
heavy rainfall (1-3 inch/hr rates).

Discussion...Strong thunderstorms continue along a couple of
axes/outflow boundaries - 1) drifting slowly northward and
extending from near Lufkin to near Alexandria, Baton Rouge, and
Slidell and 2) another migrating southeastward across northeast
Texas from near Longview to near Palestine.  Just ahead of the
storms within the pre-convective environment, strong instability
(1500-3000 J/kg MLCAPE) and 1.8 inch PW values were sustaining
intense updrafts with water loading efficient rain rates
approaching 3 inches/hr (especially in south-central Louisiana).
Meanwhile, west-northwesterly flow aloft (strongest in Texas and
ranging from 30-50 knots) was promoting modest storm organization.
 Short term trends suggest that the northeast Texas and southern
Louisiana outflow boundaries should converge in the general
vicinity of Nagodoches, TX to Natchitoches, LA in the next 1-2
hours, resulting in an uptick in convective coverage and flash
flood potential from multiple convective mergers.  Meanwhile,
south-central and south-eastern Louisiana convection will continue
to drift slowly northward or perhaps move erratically, with
continued areas of 1-3 inch/hr rain rates probable.

Eventually, widespread convective overturning should result in a
decrease in coverage and intensity through sunset.  In the
meantime, typical low spots/sensitive areas will continue to
experience flash flood potential as storms drift across the
region.  FFG thresholds are generally in the 2.5 inch/hr range
(locally lower), and will occasionally be threatened where slow
movement and/or cell mergers are most pronounced.

Cook

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...FWD...HGX...JAN...LCH...LIX...SHV...

ATTN...RFC...LMRFC...WGRFC...NWC...

LAT...LON   32799463 32309344 31869242 31359120 30768989
            29688922 29058905 29069003 29519156 30409359
            30899528 31839599 32669545